Patent GB-586915-A (GB)
Title: Improvements in or relating to fasteners and tools for operating said fasteners
IPC: B25B31/00
Filed: 1943-08-10
Abstract: 586,915. Stud fastenings ; plate clamps. BUGG, K. C. Aug. 10, 1943, No. 12909. Convention date, Jan. 21. [Class 44] [Also in Group XXIII] A stud device for securing together apertured plate members 22, 64 comprises a stud with shank 30, Fig. 1, permanently mounted in an aperture in plate 22 with a stud head 20 overlying the marginal portion of said aperture, a filling washer 32 eccentrically and rotatably mounted on the shank, a locking member 44 eccentrically, slidably, and non-rotatably mounted on the shank as by flats 42 on the shank fitting a correspondingly shaped aperture in the locking member, a sleeve 52 rotatably mounted on a reduced portion 50 of the shank and secured by riveting the shank end 54, and a compression spring 58 mounted on the sleeve between an enlargement 60 thereof and the face of the locking member. In use, members 32, 44 are positioned concentric with each other and plate 22 is applied to plate 64 so that the stud shank enters the aperture in plate 64, member 44 passing completely through the aperture and member 32 fitting in and approximately filling the aperture. The stud shank is then rotated. by screwdriver or like tool applied to a slot, not shown, in the head 20, to rotate the locking member 44 out of concentric register with member 32, the eccentric mounting of member 44 causing it to overlie a marginal mounting of the aperture in plate 64 as seen in Fig. 6. To prevent accidental rotations of the parts, plate 22 and members 32, 44 have indentations on one face producing cam ribs 36, 34, 46 on the other face, the ribs on one member nesting in the indentations of an adjacent member under action of the spring 58 which also urges member 44 towards the head 20 so that the plates are resiliently held together. The ribs ride out of the indentations when the parts are intentionally rotated. Preferably the ribs and indentations on each part are three in number radially disposed 120 degrees apart, as seen in Fig. 6, so that engagement may occur in any of three positions, in one of which the parts 32, 44 are concentric, and in the other two eccentric. Sleeve 25 has larger external diameter than the adjacent part of shank 30 to provide a shoulder 56 which abuts against member 44 in the event of applied force separating the plates, to limit such separation, the limitation preferably occuring before the spring is fully compressed, so that tensional strain is taken by the stud. Fig. 7 shows a modification in which the fastening device is entirely removable. In this case the plates have registering apertures of the same size and the filling-piece 74 provided under the head of the stud is thick enough to fill both apertures as shown and has a peripheral flange 81 overlapping the edge of the aperture in plate 22. In other respects the device resembles that of Fig. 1. A special tool, Fig. 11, is provided to operate this modification, comprising a shank 106 with handle 108 and a bit 110 to engage the screwdriver slot in the stud head, a sleeve 112 having a bit 122 to engage a slot 84 in filling- piece 74, and a knurled head 114 for manipulation of the sleeve. The sleeve is rotatable on the shank and also slidable thereon within limits imposed by a washer 118 fixed in a groove in the shank and by the length of a recess 116 enclosing the washer and closed by a cap 120. By this tool the filling-piece 74 can be held stationary whilst the stud is being rotated. A modification of the device of Fig. 7 is also described in which the sleeve 52 and spring 58 are disposed between the head of the stud and the outer face of the filling-piece 74, the locking member 44 and flats 42 being disposed at the inner end of the stud shank.